Dry air-supplying apparatus and dryer

ABSTRACT

To minimize the heat energy required for supplying dry air. A dry air-supplying apparatus  1  comprises a dry air-supplying air path  6  for supplying air from the surroundings that has been heated as dry air and a discharge air path  7  for discharging the moist air to the surroundings after the drying operation by the supplied dry air. Thus, the dry air-supplying air path draws in surrounding air and provides heat-exchanges by a heat exchanger  13  with the air in the discharge air path, this heat-exchanged air is heated by a radiator  14  and is supplied as dry air; while the discharge air path provides heat-exchanges, by the heat exchanger, the moist air after the drying operation with the air in the dry air-supplying air path, cools and dehumidifies the air that has been heat-exchanged by a cooler, and discharges it.

FIELD OF THE INVENTION

The present invention relates to a dry air-supplying apparatus forsupplying dry air to dry various items to be dried and to a dryer.

BACKGROUND OF THE INVENTION

In conventional dry air-supplying apparatuses, moist air is discharged,to the outside after the items to be dried have been subjected to adrying treatment.

Moreover, in another type of conventional dry air-supplying apparatus,as for example shown in JP, A, 2007-7155, the items to be dried aredried by hot air heated by a radiator, and the moist air, after thedrying operation, is cooled by a cooler to remove its moisture, andthereafter the air, from which the moisture has been removed, is againheated by the radiator and reused as dry air. In this manner, the air iscirculated as alternately repeating cooling and heating operations.

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

When warm moist air is discharged, as it is, to the outside, the heat ofthe warm moist air is emitted to the outside and the heat energy of themoist air is lost without being effectively used. Together with this,the humidity and temperature of the surroundings to which the air isdischarged rise, and there arises a risk that the surroundingenvironment will be significantly influenced.

If, moreover, air is circulated as repeatedly performing alternatecooling and heating operations, there is a big energy loss because itaccompanies heating cool air and cooling the warm air that has beenheated, thereby necessitating extra heating for an amount of sensibleheat.

Thus, the problem to be solved is that much energy is needed forsupplying dry air.

Means for Solving the Problems

A dry air-supplying apparatus 1 according to the present inventioncomprises a dry air-supplying air path 6 for supplying air from thesurroundings that has been heated as dry air and a discharge air path 7for discharging moist air to the surroundings after the drying operationby the supplied dry air. The dry air-supplying air path 6 draws insurrounding air and provides heat-exchanges, by a heat exchanger 13,with the air in the discharge air path, and this heat-exchanged air isheated by a radiator 14 and is supplied as dry air; while the dischargeair path provides heat-exchanges, by the heat exchanger, between themoist air after the drying operation and the air in the dryair-supplying air path, and the heat-exchanged air is cooled anddehumidified by a cooler 23, and discharged.

Furthermore, the radiator and the cooler may constitute a refrigerationcycle wherein, between the outlet 13 e of the heat exchanger at thedischarge air path and the cooler, the air from the heat exchanger maybe mixed with air from the surroundings before it flows to the cooler.

A dryer of the present invention comprises a storage compartment 52 inits casing for storing items to be dried such as clothes, a dryair-supplying air path for heating air from outside the storagecompartment and supplying said heated air to the storage compartment,and a discharge air path for discharging air from inside the storagecompartment to the outside of the storage compartment. The dryair-supplying air path draws in air from outside the storage compartmentand provides heat-exchanges by a heat exchanger with the air in thedischarge air path, this heat-exchanged air is heated by a radiator andsupplied to the storage compartment, and at the discharge air path theair from inside the storage compartment is heat-exchanged by said heatexchanger with the air in the dry air-supplying air path, this heatexchanged air is mixed with air from the space between the casing andthe storage compartment, cooled and dehumidified by a cooler and thendischarged to the outside of the storage compartment.

ADVANTAGEOUS EFFECT OF THE INVENTION

According to the present invention, when air from the surroundings isheated and supplied as dry air, the air from the surroundings isheat-exchanged by the heat exchanger with the air after the dryingoperation and, after the heat (in other words, sensible heat) has beenretrieved from the air after the drying operation, it is further heatedby the radiator and supplied as dry air. Consequently, the heat of theair that is discharged after the drying operation can be retrieved andeffectively used. Moreover, an increase in temperature and humidity ofthe environment to which the air is discharged can be prevented becausethe air used for the drying operation that comes out of the heatexchanger is discharged after it has been cooled and dehumidified by thecooler.

Furthermore, if the radiator and the cooler constitute a refrigerationcycle wherein, between the outlet of the heat exchanger at the dischargeair path and the cooler, the air from the heat exchanger is mixed withair from the surroundings before it flows to the cooler, the amount ofair flowing through the cooler can be increased and the temperature ofthe refrigerant of the cooler can be raised by mixing the air in thedischarge air path with the air from the surroundings. As a result ofwhich the efficiency of the refrigeration cycle as a heat pump can beimproved. At this juncture, the surrounding air can also bedehumidified.

Moreover, when the dry air-supplying apparatus of the present inventionis employed in a dryer having a storage compartment in its casing forstoring items to be dried such as clothes, air from the surroundings isheated and supplied as dry air to the storage compartment, hence air isnot circulated but fresh air flowing in; therefore it is possible toavoid to the utmost odors and the like remaining inside the storagecompartment. The air between the casing and the storage compartment isalso dehumidified by the cooler, therefore, the inside of the casing canalso be dried, the installation environment of electrical and otherparts inside the casing can be improved and the occurrence of mold andrust can be avoided to the utmost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of the first embodiment of a dryair-supplying apparatus according to the present invention.

FIG. 2 shows explanatory views of a heat exchanger: (a) is an explodedperspective view of the assembly, (b) is a sectional view of thepartition plate, and (c) is a sectional view of a modification of thepartition plate.

FIG. 3 shows sectional views of two modifications of the heat exchanger.

FIG. 4 shows two other modifications of the heat exchanger.

FIG. 5 shows a schematic diagram of the second embodiment of a dryeraccording to the present invention.

FIG. 6 shows a schematic diagram of the third embodiment of a dryair-supplying apparatus according to the present invention.

FIG. 7 shows a schematic diagram of the fourth embodiment of a dryair-supplying apparatus according to the present invention.

FIG. 8 shows a schematic diagram of the fifth embodiment of a dryair-supplying apparatus according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The object that is minimizing the heat energy required for supplying dryair is achieved by, when supplying air from the surroundings afterheating as dry air, heat-exchanging the air from the surroundings withthe air that has been used for the drying operation, and, after the heat(in other words, sensible heat) has been retrieved from the air that hasbeen used for the drying operation, by heating it further by theradiator and by supplying it as dry air.

Example 1

Now the first embodiment of a dry air-supplying apparatus according tothe present invention will be explained by referring to FIGS. 1 to 4.FIG. 1 shows a schematic diagram of the first embodiment of a dryair-supplying apparatus according to the present invention. FIG. 2 showsexplanatory views of a heat exchanger: (a) is an exploded perspectiveview of the assembly; (b) is a sectional view of the partition plates;and (c) is a sectional view of a modification of the partition plates.FIG. 3 shows sectional views of two modifications of the heat exchanger.FIG. 4 shows two other modifications of the heat exchanger. In FIG. 1,parts of the ducts forming air paths are shown by broken lines. Theupper plate of the heat exchanger in FIG. 2( a) is shown in atransparent state so that the shape of the partition plates below can beseen.

The air that is heated in the dry air-supplying apparatus is supplied toa drying chamber 2. The drying chamber 2 can, for example, be a storagecompartment provided in the drum of a drying and washing machine fordrying clothes after washing, an oven for drying food and food wastes, adrying chamber for drying parts that have been washed with a solvent, adrying chamber for drying dry-cleaned clothes and the like.

A dry air-supplying apparatus 1 comprises a dry air-supplying air path 6supplying dry air to the drying chamber 2 and a discharge air path 7 fordischarging air from the drying chamber 2 to the surroundings after ithas been used for the drying operation. The dry air-supplying air path 6comprises a fan 11 used for supplying dry air that is drawn into theapparatus 1 from the surrounding air (in other words, the air outsidethe drying chamber 2), a flow path of supplying side 13 a of a heatexchanger 13 into which the air drawn in by the fan 11 flows via a duct12, and a radiator 14 disposed downstream of the heat exchanger 13. Theradiator 14 is provided in a duct 17 that leads from the heat exchanger13 to the dry air-supplying opening 16 of the drying chamber 2.

The discharge air path 7 comprises a duct 22 leading from an air outlet21 of the drying chamber 2 to the heat exchanger 13, a flow path ofdischarging side 13 b of the heat exchanger 13 connected to the duct 22,a cooler 23 and a fan 24 for the cooler disposed spaced apart from andthe downstream of an outlet 13 e of the flow path of discharging side 13b. The heat exchanger 13, as will be explained hereinafter,heat-exchanges the air flowing in the flow path of supplying side 13 aand the air flowing in the flow path of discharging side 13 b withoutmixing the two. Then, when the fan 24 for the cooler is in operation,discharge air coming out of the outlet 13 e of the heat exchanger 13 ismixed with air from the surroundings, which flows into the space betweenthe heat exchanger 13 and the cooler 23, and then flows to the cooler23.

Together with a compressor 26 and an expansion valve 27, the radiator 14and the cooler 23 constitute a refrigeration cycle using a carbondioxide as a refrigerant (CO₂ refrigerant).

The compressor 26 compresses the CO₂ refrigerant in a gaseous state anddelivers the refrigerant whose pressure and temperature has increasedinto the radiator 14. The radiator 14 heat-exchanges the refrigeranthaving a high temperature with the air inside the duct 17 of the dryair-supplying air path 6, thereby air-cooling the refrigerant andheating the air in the dry air-supplying air path 6. Then, therefrigerant coming out of the radiator 14 expands and lowers in itstemperature as passing through the expansion valve 27, and flows to thecooler 23. The cooler 23 heat-exchanges the cool refrigerant with thedischarge air in the discharge air path which has been mixed with airfrom the surroundings, cools and dehumidifies the discharge air whichhas been mixed with air from the surroundings. The dew condensationwater produced at this stage drops as drain water into a drain pan 28via which it is drained off.

The heat exchanger 13, as shown in FIGS. 2( a) and 2(b), comprises aside plate 31 on the side of the dry air-supplying air path 6 of theleft side, a side plate 32 on the side of the discharge air path 7 ofthe right side, an upper plate 33, a lower plate 34, and partitionplates 36 for partitioning the flow path of supplying side 13 a from theflow path of discharging side 13 b. This partition plate 36 alsofunctions as the front plate and the back plate of the heat exchanger13. The in- and outlets 13 c to 13 f of the flow path of supplying side13 a and the flow path of discharging side 13 b are formed on the sideplates 31 and 32. The inlet 13 c of the flow path of supplying side 13 ais formed at the lower side, while the inlet 13 f of the flow path ofdischarging side 13 b is formed at the upper side; the flow through theflow path of supplying side 13 a and the flow through the flow path ofdischarging side 13 b are constituted so as to be oriented in oppositedirections.

The partition plate 36 for partitioning the interior of the heatexchanger 13 are formed from metal plates of a material with high heattransfer properties such as copper, aluminium or the like so as to allowthe heat exchange between the air in the flow path of supplying side 13a and the air in the flow path of discharging side 13 b. The side plates31, 32, the upper plate 33 and the lower plate 34 which form theexternal contour of the heat exchanger 13 can be made of metal plates orplates made from resins or other materials.

The partition plates 36 shown in FIGS. 2( a) and 2(b) are formed byrepeated bending into a shape approximately resembling the letter U laidon its side; however, they can also be formed by repeated bending intothe shape of the letter V laid on its side, as shown by the modificationin FIG. 2( c).

It is also possible to partition the interior space of the heatexchanger 13 into two parts by a flat partition plate 36 as in anothermodification shown in FIG. 3( a). Moreover, in the modification shown inFIG. 3( b), the external contour of the heat exchanger 13 is constitutedby a cylindrical member 35. In other words, in the modification of FIG.3( a), the section of the external contour of the heat exchanger 13 isrectangular, while in the modification of FIG. 3( b) it is circular.

In another modification shown in FIG. 4( a), it is also possible to formthe flow path of supplying side 13 a and the flow path of dischargingside 13 b by partitioning the interior space of the heat exchanger 13into two parts by a flat partition plate 37, and to provide a pluralityof approximately L-shaped heat transfer fins 38 disposed at someintervals in each of the flow paths 13 a, 13 b. The bent ends of theseapproximately L-shaped heat transfer fins 38 are welded onto thepartition plate 37. The heat transfer fins 38, like the partition plates36, 37, are formed from metal plates of a material with high heattransfer properties such as copper, aluminium or the like so as to allowheat exchanges between the air in the flow path of supplying side 13 aand the air in the flow path of the discharging side 13 b.

Yet in another modification shown in FIG. 4( b), it is also possible todivide the interior space of the heat exchanger 13 into a plurality ofdivisions by a plurality of heat transfer fins 41 and to partition eachof these divided spaces into two parts by partition plates 42approximately resembling the shape of the letter U laid on its side. Theheat transfer fins 41 and partition plates 42, like the above-mentionedheat transfer fins 38 and partition plates 36, 37, are made of amaterial with high heat transfer properties.

In this way, the heat exchanger 13 is constituted so as to allow theheat exchange between the air in the flow path of supplying side 13 aand the air in the flow path of discharging side 13 b without mixing thetwo.

In order to supply dry air by a dry air-supplying apparatus 1constituted in this way, the fan 11, the compressor 26 and the fan 24for the cooler are set in operation. Whereupon the air from thesurroundings (in other words, air from outside the drying chamber 2)that is drawn into the dry air-supplying air path 6 by the fan 11 flowsinto the flow path of supplying side 13 a of the heat exchanger 13 viathe duct 12. The temperature of the air flowing through the flow path ofsupplying side 13 a increases when it is heat-exchanged by the heatexchanger 13 with air having a high temperature that flows in the flowpath of discharging side 13 b from the drying chamber 2. Followingwhich, it is further heated by the radiator 14 and supplied as hightemperature dry air to the drying chamber 2 through the dryair-supplying opening 16. The dry air supplied to the drying chamber 2dries the items to be dried in the drying chamber 2. Accompanying this,there is an increase in the humidity of the dry air together with asmall drop in temperature.

The moist air inside the drying chamber 2 flows from the air outlet 21of the drying chamber 2 into the discharge air path 7. The temperatureof the moist air that flows into the discharge air path 7 is lower thanthat of the dry air and higher than that of the surrounding air. Themoist air that flows into the discharge air path 7 then flows in theflow path of discharging side 13 b of the heat exchanger 13 whereuponits temperature is decreased as it is heat-exchanged in the heatexchanger 13 with air from the surroundings flowing in the flow path ofsupplying side 13 a. Following which, it comes out from the outlet 13 eof the discharge side flow path 13 b, is mixed with air from thesurroundings, cooled and dehumidified by the cooler 23 and discharged.The dew condensation water produced during dehumidification drops asdrain water into a drain pan 28 and is drained off. When dry air issupplied from the dry air-supplying apparatus 1 to the drying chamber 2,the rotational speed of the fan 11, the compressor 26 and the fan 24 forthe cooler together with the degree of opening of the expansion valve 27can be suitably adjusted in accordance with the load of the dryingchamber 2 and the like.

Thus, air from the surroundings is heat-exchanged by the heat exchanger13 with air from the drying chamber that has been used for the dryingoperation and, after the heat (in other words, sensible heat) has beenretrieved from the air out of the drying chamber 2 that has been usedfor the drying operation, it is further heated by the radiator 14 andsupplied as dry air to the drying chamber 2. Consequently, the heat ofthe air that is being discharged from the drying chamber 2 after thedrying operation can be effectively used.

An increase in temperature and humidity of the environment to which theair is discharged can be prevented because the air that comes out of theheat exchanger 13 is discharged after it has been cooled anddehumidified by the cooler 23.

The moist air coming out of the heat exchanger 13 is mixed with air fromthe surroundings and flows to the cooler 23. This cooler 23 mayconstitute together with the radiator 14 a refrigeration cycle as a heatpump, whereby the amount of air flowing through the cooler 23 can beincreased and the temperature of the refrigerant of the cooler 23 can beraised by mixing the moist air with air from the surroundings. As aresult of which the efficiency of the refrigeration cycle as a heat pumpcan be improved. At this juncture, moreover, the surrounding air can bedehumidified.

Moreover, due to leakage from the drying chamber 2 through its door andsuch places, there is a drop in the amount of air that is fed into thedry air-supplying air path 6 by the fan 11 from the surroundings when itflows between the air paths 6, 7 and the drying chamber 2; therefore,the amount of air in the flow path of discharging side 13 b of the heatexchanger 13 is less than the amount of air that flows in the radiator14. Consequently, the amount of air flowing to the cooler 23 can beassured by supplementing the air from the flow path of discharging side13 b of the heat exchanger 13 with air from the surroundings before itis fed to the cooler 23.

Example 2

Next, the second embodiment of a dry air-supplying apparatus accordingto the present invention will be explained. FIG. 5 shows a schematicdiagram of the second embodiment of a dryer according to the presentinvention. Furthermore, in the explanation of the second embodiment, itsconstituent elements that correspond to constituent elements in thefirst embodiment have the same reference numerals as in the firstembodiment, and their detailed explanation is omitted.

In the second embodiment of a dry air-supplying apparatus, the dryair-supplying apparatus according to the first embodiment is used in adrum type drying and washing machine, wherein the dry air-supplyingapparatus 1 according to the first embodiments provided inside thedryer. The dry air-supplying apparatus 1 of the second embodiment hasthe same constitution as the dry air-supplying apparatus 1 according tothe first embodiment.

A casing 51 of a drum type drying and washing machine is constituted bya cabinet that is open at the bottom; inside this casing 51, the storagecompartment 52, which corresponds to the drying chamber 2 in the firstembodiment, is provided for storing items to be dried such as laundry. Adrum (not shown in the drawing) for loading clothes is provided insidethis storage compartment 52 so as to be rotatable; this drum, whichfunctions as a stirring device, is rotated by a driving motor. A frontopening of the casing 51 is closed by a door 56 so that it can be openedand closed. This door 56 is opened for loading clothes into the drum ofthe storage compartment.

An air delivery opening 61 for supplying air (dry air) into the storagecompartment 52 and an air discharge opening 62 for discharging the air(moist air) from inside the storage compartment 52 are provided in thestorage compartment 52; the outlet of the dry air-supplying air path 6of the dry air-supplying apparatus 1 is connected to the air deliveryopening 61, while the inlet of the discharge air path 7 of the dryair-supplying apparatus 1 is connected to the air discharge opening 62.

When wet clothes are dried in a dryer constituted in this way, the door56 is opened, the clothes are loaded into the storage compartment 52 andthe door 56 is closed after loading. Then, the dry air-supplyingapparatus is set in operation, air (surrounding air) is drawn in fromthe space between the casing 51 and the storage compartment 52 and issupplied as dry air via the heat exchanger 13 and the radiator 14through the air delivery opening 61 to the storage compartment 52. Theclothes are dried by the dry air that is being supplied while the drum(not shown in the drawing) of the storage compartment 52 is rotated.Then, the moist air in the storage compartment 52 after the dryingoperation comes out from the air discharge opening 62, is heat-exchangedby the heat exchanger, mixed with air (surrounding air) from between thecasing 51 and the storage compartment 52, cooled and dehumidified by thecooler, and discharged to the outside of the storage compartment 52.

Air can circulate in the space between the casing 51 and the storagecompartment 52 and the space outside the casing 51 because the bottom ofthe casing 51 is open. Consequently, the air outside the casing 51 canalso be drawn into the dry air-supplying apparatus 1 via the spacebetween the casing 51 and the storage compartment 52. Furthermore, airfrom the dry air-supplying apparatus 1 can also be discharged to theoutside of the casing 51 via the space between the casing 51 and thestorage compartment 52.

Thus, air from the surroundings is heated and supplied as dry air to thestorage compartment 52, hence air is not circulated but fresh air isblown in; therefore it is possible to avoid to the utmost odors and thelike lingering inside the storage compartment 52. The air between thecasing 51 and the storage compartment 52 is also dehumidified by thecooler 23, therefore, the inside of the casing 51 can also be dried, theinstallation environment of electrical and other parts inside the casing51 can be improved and the occurrence of mold and rust can be avoided tothe utmost.

Example 3

Next, the third embodiment of a dry air-supplying apparatus according tothe present invention will be explained. FIG. 6 shows a schematicdiagram of the third embodiment of a dry air-supplying apparatusaccording to the present invention. In the explanation of the thirdembodiment, the constituent elements, which correspond to constituentelements in the first embodiment, have the same reference numerals as inthe first embodiment, and their detailed explanation is omitted.

The structure of the dry air-supplying apparatus 1 according to thethird embodiment differs in the following three points from the firstembodiment of the dry air-supplying apparatus 1:

(1) The radiator 14 and the cooler 23 in the third embodiment do notconstitute a refrigeration cycle.

In the third embodiment, the radiator 14 is constituted by an electricalheater or the like, and the cooler 23 is cooled with a refrigerant fromanother cooling source.

(2) In the third embodiment, a duct 66 is provided between the outlet 13e of the flow path of discharging side 13 b of the heat exchanger 13 andthe cooler 23. Openings 67 for taking in air from the surroundings areprovided in the side faces of this duct 66; it is possible to mix theair from the surroundings that flows into these openings 67 with the airfrom the heat exchanger 13 when it flows to the cooler 23.

(3) Since the duct 66 is provided in the third embodiment, the air fromthe heat exchanger 13 is guided by the duct 66 and flows to the cooler23. Consequently, a fan 24 for the cooler is not provided.

In the dry air-supplying apparatus 1 according to the third embodimentconstituted in this way, in the same way as in the first embodiment ofthe dry air-supplying apparatus 1, the heat of the air that isdischarged from the drying chamber 2 after the drying operation can alsobe retrieved at the heat exchanger 13 and effectively used. Moreover, anincrease in temperature and humidity of the environment to which the airis discharged can be prevented because the air that comes out of theheat exchanger 13 is discharged after it has been cooled anddehumidified by the cooler 23.

Example 4

Next, the fourth embodiment of a dry air-supplying apparatus accordingto the present invention will be explained. FIG. 7 shows a schematicdiagram of the fourth embodiment of a dry air-supplying apparatusaccording to the present invention. Furthermore, in the explanation ofthe fourth embodiment, the constituent elements, which correspond toconstituent elements in the first embodiment have the same referencenumerals as in the first embodiment, and their detailed explanation isomitted. In FIG. 7 the ducts are not shown; however, the ducts areprovided in the same manner as in the first embodiment.

The dry air-supplying apparatus 1 according to the fourth embodimentdiffers from the dry air-supplying apparatus 1 according to the fourthembodiment in that a sub-radiator 71 is provided; the remainingstructure is identical.

In the refrigerant flow of the refrigeration cycle, the sub-radiator 71is provided between the radiator 14 and the expansion valve 27 (in otherwords, downstream of the radiator 14 and upstream of the expansion valve27). In the air flow of the dry air-supplying air path 6, thesub-radiator 71 is placed upstream of the heat exchanger 13. In thefourth embodiment, it is provided between the fan 11 and the heatexchanger 13.

In the first embodiment, in which the refrigerant that flows to theexpansion valve 27 is air-cooled by warm air after the moist air fromthe drying chamber 2 has been heat-exchanged, the temperature cannot besufficiently lowered and the efficiency of the refrigeration cycle isdecreased. In the fourth embodiment, on the contrary, in which therefrigerant that flows to the expansion valve 27 is air-cooled in thesub-radiator 71 by air from the surroundings, the temperature can besufficiently lowered and the efficiency of the refrigeration cycle canbe improved.

In the dry air-supplying apparatus 1 according to the fourth embodimentconstituted in this way, in the same way as in the first embodiment ofthe dry air-supplying apparatus 1, the heat of the air that isdischarged from the drying chamber 2 after the drying operation can alsobe retrieved at the heat exchanger 13 and effectively used. Moreover, anincrease in temperature and humidity of the environment to which the airis discharged can be prevented because the air that comes out of theheat exchanger 13 is discharged after it has been cooled anddehumidified by the cooler 23.

Example 5

Next, the fifth embodiment of a dry air-supplying apparatus according tothe present invention will be explained. FIG. 8 shows a schematicdiagram of the fifth embodiment of a dry air-supplying apparatusaccording to the present invention. In the explanation of the fifthembodiment, the constituent elements, which correspond to constituentelements in the first embodiment have the same reference numerals as inthe first embodiment, and their detailed explanation is omitted.Moreover, in FIG. 8 the ducts are not shown and the arrows showing theair flow inside the heat exchanger 13 and the like are omitted; however,the ducts are provided and the air flow inside the heat exchanger 13 isidentical to the first embodiment.

The dry air-supplying apparatus 1 according to the fifth embodimentdiffers from the first embodiment of the dry air-supplying apparatus 1in that a sub-radiator 81 is provided in the drain pan 28; the remainingstructure is identical.

In the refrigerant flow in the refrigeration cycle, the sub-radiator 81according to the fifth embodiment is provided between the radiator 14and the expansion valve 27 (in other words, downstream of the radiator14 and upstream of the expansion valve 27) in a similar manner as thesub-radiator 71 of the fourth embodiment.

The dew condensation water produced during cooling by the cooler 23drops into the drain pan 28 and is drained as drain water into a seweror the like. This drain water has a low temperature as it is cooled bythe cooler 23; by cooling the sub-radiator 81 with this low temperaturedrain water, the thermal energy of the drain water can be retrieved andthe efficiency of the refrigeration cycle can be improved.

In the dry air-supplying apparatus 1 according to the fifth embodimentconstituted in this way, in the same way as in the first embodiment ofthe dry air-supplying apparatus 1, the heat of the air that isdischarged from the drying chamber 2 after the drying operation can alsobe retrieved at the heat exchanger 13 and effectively used. Moreover, anincrease in temperature and humidity of the environment to which the airis discharged can be prevented because the air that comes out of theheat exchanger 13 is discharged after it has been cooled anddehumidified by the cooler 23.

The embodiments of the present invention have been explained in detailabove; however, the present invention is not limited to theseembodiments, and it is possible to make various modifications within thescope of the gist of the present invention stated in the claims.

Examples of modifications of the present invention are as follows:

(1) The heat exchanger 13 is assembled by welding; however, the assemblystructure can be suitably selected, it can, for example, be assembled byfitting or the like.(2) The position, structure and shape of the fan 11 can be suitablymodified as long as it can draw in air from the surroundings and feed itto the drying chamber 2 via the heat exchanger 13 and the radiator 14.(3) It is also possible to form holes in the side faces or the like ofthe casing 51 of the drying and washing machine.(4) Air from the surroundings is admixed between the outlet 13 e of thedischarge air path 7 of the heat exchanger 13 and the cooler 23;however, it is also possible not to admix air from the surroundings. Inother words, the outlet 13 e of the discharge air path 7 and the cooler23 can also be connected by a duct not having the openings 67 for takingin air from the surroundings. It is, however, preferred to admix airfrom the surroundings before air flows to the cooler 23.(5) It is most preferred that the refrigerant is carbon dioxide (CO₂);however, other refrigerants are also possible.(6) It is preferred that the radiator 14 is a gas cooler or a condenserof a refrigeration cycle; however, it can also be an electric heater, agas heater, a burner or the like.(7) In the third, the fourth or the fifth embodiments, of the dryair-supplying apparatuses, a drum type drying and washing machine in thesame way as the second embodiment can also be used.(8) In the dry air-supplying apparatus inside a drum type drying andwashing machine, the air that is dehumidified by the cooler isdischarged to the space between the casing and the storage compartment;however, it is also possible to discharge it to the outside of thecasing. In the same way, in the dry air-supplying apparatus inside adrum type drying and washing machine, the air drawn into the dryair-supplying air path by the fan is the air in the space between thecasing and the storage compartment, but can also be the air outside thecasing. Yet it is preferred that the air from the surroundings admixedin between the heat exchanger and the cooler is from the air in thespace between the casing and the storage compartment.

INDUSTRIAL APPLICABILITY

When air from the surroundings is heated and supplied as dry air, theair from the surroundings is heat-exchanged by the heat exchanger withthe air after the drying operation and, after the heat (in other words,sensible heat) has been retrieved from the air after the dryingoperation, it is further heated by the radiator and used as dry air,whereby dry air can be supplied with little energy. Consequently, it ismost preferred to apply this to a dry air-supplying apparatus forsupplying dry air and to a dryer.

EXPLANATION OF THE REFERENCE NUMERALS

-   -   1 Dry air-supplying apparatus    -   6 Dry air-supplying air path    -   7 Discharge air path    -   13 Heat exchanger    -   13 e Outlet of the heat exchanger    -   14 Radiator    -   23 Cooler    -   51 Casing of the dryer    -   52 Storage compartment of the dryer

1. A dry air-supplying apparatus comprising: a dry air-supplying airpath for supplying air from surroundings that has been heated as dry airand; a discharge air path for discharging moist air to the surroundingsafter the drying operation by the supplied dry air, wherein the dryair-supplying air path draws in surrounding air and providesheat-exchanges with the air in the discharge air path by a heatexchanger, and supplies the heat-exchanged air that is heated thereafterby a radiator as dry air, wherein the discharge air path providesheat-exchanges, by the heat exchanger, between the moist air after thedrying operation and the air in the dry air-supplying air path, andcools and dehumidifies the air that has been heat-exchanged by a cooler,and discharges it.
 2. A dry air-supplying apparatus according to claim1, wherein the radiator and the cooler constitute a refrigeration cycle,wherein, between the outlet of the heat exchanger and the cooler at thedischarge path, the air from the heat exchanger is mixed with air fromthe surroundings before it flows to the cooler.
 3. A dryer having astorage compartment in its casing for storing items to be dried such asclothes, the dryer comprising: a dry air-supplying air path for heatingair from outside the storage compartment and supplying said heated airto the storage compartment; a discharge air path for discharging airinside the storage compartment to the outside of the storagecompartment, wherein the dry air-supplying air path draws in air fromoutside the storage compartment and provides heat-exchanges with the airin the discharge air path by a heat exchanger, and supplies theheat-exchanged air, after it is heated by a radiator to the storagecompartment, wherein the discharge air path provides heat-exchanges, bythe heat-exchanger, between the air from inside the storage compartmentand the air in the dry air-supplying air path, and provides mixing ofair from the space between the casing and the storage compartment intothe heat-exchanged air, and cools, and dehumidifies by a cooler, anddischarges it to the outside of the storage compartment.